The present invention relates to a lens-fitted photographic film unit, and more particularly to a disposable lens-fitted film unit with an electronic flash.
Recently, there have come on the market disposable or single-use lens-fitted photographic film units which have a roll of film and a simple exposure mechanism incorporated in a casing. Because such a lens-fitted photographic film unit can be sold wherever photographic film is sold, if one who takes no camera along but wants to take pictures, it is easy to get a new lens-fitted photographic film unit and to take pictures without a camera.
To provide such lens-fitted photographic film units at low cost, a simple shutter is used to give a single shutter speed such as 1/100 sec. On the other hand, the film used in such a lens-fitted photographic film unit has a relatively wide range of latitude of exposure. Although such a single shutter speed is employed and the photographic film used in the lens-fitted photographic film unit has a relatively wide exposure range, nevertheless it is relatively hard to cover high or low brightness objects.
Recent photofinishing techniques make it possible to a certain extent to make prints with proper density from negatives of images of subjects whose brightness is relatively high or relatively low. However, it remains frequently difficult to make prints from negatives of images of objects of too low brightness. In consideration of this, it has been proposed to use a disposable electronic flash either built in or removably attached to the lens-fitted photographic film unit, to cover the low end of the brightness range.
After all of the frames of film in the film unit, either with a built-in electronic flash or with a disposable electronic flash attached thereto, have been exposed, the film unit, with its associated electronic flash, is forwarded to a photo shop or photo laboratory to develop the exposed film and to make prints from the developed film. At that place, after removing the exposed film, the used film unit with its electronic flash is scrapped.
Since batteries contain poisonous substances such as mercury or mercury compounds which cause harm to the public, the batteries have to be removed from the used film units before scrapping them. Usually, a battery is incorporated either in a film unit housing or in an electronic flash housing. For removing the battery from the film unit housing or the electronic flash unit housing, it is necessary to destroy the housing. This is a somewhat troublesome task in photo shops or photo laboratories.